The invention relates to hydrostatic axial thrust bearings especially high speed, high pressure hydrostatic bearings.
Hydrostatic axial thrust bearings can carry relatively large loads, are relatively inexpensive and are quite efficient. They are also accurate in positioning two relatively movable structures if the hydraulic bearing pad between the two relatively movable bearing structures is thin or a bearing cavity seal is closely adjacent the structure to be sealed. A major problem, however, resides in wear and scratching of the harder element of the seal or other mating structural areas. It appears that hard abrasive particles are implanted into the softer of the two mating surface areas and, embedded therein, they lap and grind down the harder of the two surfaces. Even very fine filters such as 10 micron lubricant filters have been found to be ineffective in preventing surface scratching and wear.
Resilient bearing surfaces have been proposed (U.S. Pat. No. 2,887,766) and have been found to be effective to some degree but highly resilient surfaces have been subject to wear particularly on the radially outer edges of the bearing seal surfaces.
It has been found that the wear at the outer edges of the bearing seal faces results actually from a deformation of the resilient surfaces caused by the pressure of the lubricant flowing through the gap between the seal surfaces. It was found that this pressure causes the outer edges to grow out of the plane of the seal faces and finally into contact with the opposite seal face resulting in wear and even melting of the outer edges of the seal faces.